The present invention relates to apparatus and methods for testing multiconductor data cables.
Multiconductor data cables are widely utilized in the data communications field. For example, such cables are employed in connecting remote terminals to computers. Data cables typically must provide many separate circuits to perform various specialized functions. Many common data cables are constructed according to the EIA (Electronic Industries Association) standard RS-232C. Cables according to this standard may have 25 separate conductors and may be provided at each end with connectors having 25 separate connecting elements such as pins or sockets. The individual pins or sockets of such connectors are designated according to a predetermined numbering scheme. In a simple or "straight through" cable, each connecting element of one connector is connected only to the corresponding element of the connector at the opposite end of the cable. Many cables, however, employ customized interconnection patterns. Thus, some of the conductors or elements in the connectors may be omitted. Also, some of the conductors may interconnect differently designated elements in the two conductors as, for example, where element number two of one connector is connected to element number three of the connector on the opposite end of the cable and vice versa. Also, some of the elements of a connector may be interconnected with one another. Testing all of the separate circuits provided by a typical data cable, and checking the pattern of interconnections in the cable is a difficult task. These difficulties are aggravated if an already installed cable must be tested. Thus, the two ends of the cable may be disposed in two different rooms.
Although numerous portable devices have been used by field service technicians for testing data cables, none of these have been truly satisfactory in all respects. Some simple devices can be used only where both ends of the cable are in close proximity to one another, and hence cannot be used to test an installed cable. Other portable cable testers which can be used to test an installed cable are expensive or are incapable of testing all aspects of cable configuration. Thus, there has been a significant need for improved data cable testing apparatus, and similar needs for improved methods of testing a data cable.